Hexagonal Ball Grid Array for Signal Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed ball grid array (BGA) semiconductor packages face challenges with electromagnetic interference (EMI) and signal integrity, particularly in high-speed IC applications, where traditional square grid arrays are insufficient in managing impedance and signal density.
Innovation Solution
Implementing a hexagonal ball-grid array with specific pin assignments for power, ground, and signal pins, utilizing nested hexagonal patterns and offset arrangements to optimize signal-to-power/ground ratios, thereby improving electrical performance and reducing electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional square grid array is used for BGA packaging, then the package structure is simple and easy to manufacture, but electromagnetic interference increases and signal integrity deteriorates in high-speed applications
Solution Approach 1:
The patent transitions from a traditional square grid array to a hexagonal ball grid array configuration. The hexagonal pattern provides asymmetric geometric properties that improve signal integrity by reducing electromagnetic interference and optimizing impedance control for high-speed differential signals, while maintaining manufacturing feasibility through established BGA fabrication processes
Solution Approach 2:
The patent introduces a new dimensional approach by arranging balls in a hexagonal pattern rather than a square grid. This dimensional change in the spatial arrangement of balls creates optimized signal paths and power/ground relationships that reduce EMI and improve signal integrity for high-speed applications
2Quantity of substance
If I/O density is increased in BGA packaging, then more signals can be accommodated in a given package size, but electromagnetic interference becomes more severe
Solution Approach 1:
The patent applies local quality optimization by strategically assigning specific hexagonal ball positions to power, ground, and signal functions. The pin assignment patterns create localized power/ground pairs and signal differential pairs that minimize EMI while maximizing I/O density. Different regions of the hexagonal array are optimized for different functions to reduce overall electromagnetic interference
Solution Approach 2:
The patent converts the potentially harmful effect of high I/O density (which increases EMI) into a benefit by using the hexagonal configuration to create optimized power/ground and signal pair arrangements. The close proximity of balls in the dense hexagonal pattern, which would normally increase interference, is instead used to create tightly coupled differential pairs and well-balanced power/ground relationships that reduce EMI
3Reliability
If impedance control is optimized for high-speed signals, then signal integrity improves, but package design complexity increases
Solution Approach 1:
The patent changes the geometric parameters of the ball array from a square grid to a hexagonal pattern, which fundamentally alters the impedance characteristics. The hexagonal configuration provides natural impedance control for high-speed differential signals by optimizing the spacing and arrangement of power, ground, and signal balls, reducing the need for complex additional impedance control measures
Data Source
AI summary
An improved system and method for assigning power and ground pins and single ended or differential signal pairs for a ball grid array semiconductor package. In certain embodiments, the system uses a hexagonal pattern where the grid may be represented by a multiplicity of nested hexagonal patterns.